The present invention relates generally to a cable with a sheath having improved mechanical flexibility and for better facilitating a connector terminal. More specifically, the invention relates to a cable having a cylindrical sheath wherein a ribbon cable including a plurality of discrete core wires is folded.
Sheathed multiconductor cables comprising a plurality of discrete core wires are generally useful for making connections between electronic communication devices or so forth. The core of such cables is generally formed by forming a ribbon comprised of a plurality of core wires, each of which is covered by an insulating material arranged parallel to each other and which are connected by bonding or fusing the insulating material. This ribbon is folded in the longitudinal direction and covered by a cylindrical sheath. Such cables have good mechanical flexibility and terminal treatment is easy.
Japanese Utility Model First Publication (jikkaisho) No. 53-59671 exemplifies one such conventional cable with a sheath. In the cable, conductor ribbon cable is folded into a spiral and wrapped with the sheath. The cable has good mechanical flexibility. However, when terminal treatment is carried out, that is, the end sheath of the cable is stripped so as to expose the flat cable and the exposed cable is extended to be connected to a line connector, a long exposed length of the ribbon is necessary.
Further, Japanese Patent First Publication (tokkaisho) No. 59671 exemplifies a conventional covered cable having a ribbon cable which is adapted for facilitating terminal treatment with a shorter exposed length of the ribbon cable. The ribbon cable is folded so as to form pleats and is covered with a sheath. The pleated ribbon type cable however has the disadvantage that the top portions of the pleats tend to be creased which stretches or distorts the insulation, thus decreasing pitch accuracy between core wires of the ribbon cable. This results in increased difficulty in connecting the conductors of the ribbon cable to the pins of the line connector. Moreover, bending in the lateral direction of the pleats becomes difficult, reducing the flexibility of the cable in lateral directions.